<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        #big {
            width: 430px;
            height: 430px;
            border: 1px solid;
        }

        #small {
            width: 430px;
            display: flex;
            justify-content: space-between;
            margin-top: 1em;

        }

        #small>img {
            width: 60px;
            height: 60px;
            border: 1px solid;
            padding: 5px;
        }
    </style>
</head>

<body>
    <div id="big">
        <img src="./点击图片/大图（1）.jpg" alt="" id="photo">
    </div>
    <div id="small">
        <img src="./点击图片/小图（1）.jpg" alt="">
        <img src="./点击图片/小图（2）.jpg" alt="">
        <img src="./点击图片/小图（3）.jpg" alt="">
    </div>
    <script>
        let img = document.querySelectorAll('#small>img');//小图
        let arr = ["./点击图片/大图（1）.jpg", "./点击图片/大图（2）.jpg", "./点击图片/大图（3）.jpg"];
        let photo = document.getElementById('photo');//大

        for (let index in img) {
            img[index].onmouseenter=function(){
                photo.src=`${arr[index]}`
            }
        }
    </script>
</body>

</html>